cifs: add routines to build sessions and tcons on the fly
This patch is rather large, but it's a bit difficult to do piecemeal...
For non-multiuser mounts, everything will basically work as it does
today. A call to cifs_sb_tlink will return the "master" tcon link.
Turn the tcon pointer in the cifs_sb into a radix tree that uses the
fsuid of the process as a key. The value is a new "tcon_link" struct
that contains info about a tcon that's under construction.
When a new process needs a tcon, it'll call cifs_sb_tcon. That will
then look up the tcon_link in the radix tree. If it exists and is
valid, it's returned.
If it doesn't exist, then we stuff a new tcon_link into the tree and
mark it as pending and then go and try to build the session/tcon.
If that works, the tcon pointer in the tcon_link is updated and the
pending flag is cleared.
If the construction fails, then we set the tcon pointer to an ERR_PTR
and clear the pending flag.
If the radix tree is searched and the tcon_link is marked pending
then we go to sleep and wait for the pending flag to be cleared.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d532485..9a7c472 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -317,42 +317,36 @@
* "get" on the container.
*/
struct tcon_link {
- spinlock_t tl_lock;
- u32 tl_count;
- u64 tl_time;
+ unsigned long tl_index;
+ unsigned long tl_flags;
+#define TCON_LINK_MASTER 0
+#define TCON_LINK_PENDING 1
+#define TCON_LINK_IN_TREE 2
+ unsigned long tl_time;
+ atomic_t tl_count;
struct cifsTconInfo *tl_tcon;
};
-static inline struct tcon_link *
-cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
-{
- return (struct tcon_link *)cifs_sb->ptcon;
-}
+extern struct tcon_link *cifs_sb_tlink(struct cifs_sb_info *cifs_sb);
static inline struct cifsTconInfo *
tlink_tcon(struct tcon_link *tlink)
{
- return (struct cifsTconInfo *)tlink;
+ return tlink->tl_tcon;
}
-static inline void
-cifs_put_tlink(struct tcon_link *tlink)
-{
- return;
-}
+extern void cifs_put_tlink(struct tcon_link *tlink);
static inline struct tcon_link *
cifs_get_tlink(struct tcon_link *tlink)
{
+ if (tlink && !IS_ERR(tlink))
+ atomic_inc(&tlink->tl_count);
return tlink;
}
/* This function is always expected to succeed */
-static inline struct cifsTconInfo *
-cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
-{
- return cifs_sb->ptcon;
-}
+extern struct cifsTconInfo *cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb);
/*
* This info hangs off the cifsFileInfo structure, pointed to by llist.